Question: If $4a + 4b = -1$ and $5x + 8y = -4$, what is $36b - 5x - 8y + 36a$ ?
Explanation: $= 36a + 36b - 5x - 8y$ $= (9) \cdot (4a + 4b) + (-1) \cdot (5x + 8y)$ $= (9) \cdot (-1) + (-1) \cdot (-4)$ $= -9 + 4$ $= -5$